Oven door construction



April 22, 1969 c. w. TlLUS OVEN DOOR CONSTRUCTION Filed Sept. 23. 1966FIG.5

United States Patent 3,439,668 OVEN DOOR CONSTRUCTION Carl W. Tilus,Mansfield, Ohio, assignor to Westinghouse Electric Corporation,Pittsburgh, Pa., a corporation of Pennsylvania Filed Sept. 23, 1966,Ser. No. 581,582 Int. Cl. F24c /02 US. Cl. 126190 4 Claims ABSTRACT OFTHE DISCLOSURE This invention relates generally to oven doorconstruction and in particular to an improved door seal construction.

While a construction according to the invention is applicable to othertypes of ovens, it is especially useful with those ovens adapted toundergo a heat-cleaning cycle involving oven temperatures substantiallyabove the usual cooking temperatures, and accordingly will be describedprincipally in that connection.

Sealing of the door of heat cleaning ovens is critical within limitssince high temperatures must be maintained to effect the cleaning (toogreat a fiow of air into the oven would increase the difficulty ofobtaining the high temperatures), but some air must be introduced topermit more complete oxidation of the material being burned from theinterior oven surfaces. A woven glass fiber material lends itself to useas a gasket for the door seal because of its ability to withstand hightemperatures while retaining adequate resiliency for sealing purposes.However, its use also poses problems stemming from the characteristicsof the fibers and of the fabric woven from the fibers. Essentially, thedifficulty experienced with woven glass fiber material is that it doesnot facilitate the usual type of mechanical mounting because of its lackof mechanical integrity, its flexural weakness and lack of sufiicientpermanent rigidity to make it self-supporting. Woven asbestos materialhas much the same character as woven glass fibers with respect to thisinvention, and, accordingly, is also applicable for use.

The general object of this invention is the provision of an oven doorconstruction in which the deficiencies of the woven fiber gasket areminimized by virtue of the mounting arrangement according to theinvention.

In accordance with the invention, the gasket material comprises a wovenfiber sleeve which is slipped over a wire frame which gives the sleeveits general configuration. The sleeve and contained frame are thenadapted to be held in the proper place on the inner face of the ovendoor by being disposed in captured relation between the peripheral edgesof a muffle panel and an inside corner formed by shoulder means on therear face of the inner panel. The wire frame is sized relative to theshoulder means on the inner panel and to extend along the inner marginof the sleeve and form, in effect, a thickened bead portion along themargin. It is this head so formed which is captured and retained betweenthe inner panel shoulder means and the mufile panel edge flange. Themufiie panel is fastened to the inner panel so that the gap between themufile panel flange and the opposing ice surface of the inner panelaccommodates a double thickness of the sleeve without fracturing forcebeing exerted upon the gasket material, but with the gap being limitedsufficiently to prevent the escape of the bead. Thus the sleeve is heldin a generally flattened condition with its major width portion (outsideof its inner margin) exposed around the perimeter of the muffle panel.Thus when the door is moved into a closed position the exposed portionof the gasket moves into sealing engagement with the oven liner throat.

The construction is such that the wire frame may be simply fastened tothe inner panel at the two ends of the frame. Other than this fastening,the remainder of the gasket is held in place by virtue of the fastenedrelationship between the muflle panel and the inner panel of the door.

An embodiment of the invention will be described by way of example inconnection with the accompanying drawing wherein:

FIGURE 1 is an isometric view of a cooking range having an oven doorconstruction according to the invention;

FIG. 2 is a partly-broken face view of the inner face of the oven door;

FIG. 3 is a sectional view corresponding to one taken along the lineIIIIII of FIG. 2;

FIG. 4 is a view of the wire frame over which the gasket is slipped;

FIG. 5 is a sectional view corresponding to one taken along line VV ofFIG. 2 and showing the end fastening arrangement;

FIG. 6 is a sectional view corresponding to one taken along the lineVIVI of FIG. 2 and showing the means for fastening the mufile panel tothe inner panel.

Referring to FIG. 1, the range illustrated may be considered to be ofthe type provided with an oven adapted to undergo a heat cleaningoperation in which food residue is burned out of the oven by subjectingthe oven to high temperatures substantially above those encountered innormal oven cooking operations. The front face of the oven cavity 10 isadapted to be closed substantially by the oven door 12. The main partsof the door of immediate interest include an outer panel 14, an opposinginner panel 16, a muffie panel 18 which generally overlies the centralarea of the inner panel, and the sealing gasket 20 which borders all ofthe edges of the muffle panel except for a part of the edge adjacent thehinged edge of the door.

The throat of the oven cavity is defined by generally outwardly-directedflanges 22 of the oven liner. These include portions projecting slightlyforwardly of the bordering front face of the range body to form a rim.When the oven door 12 is closed the gasket 20 is correspondingly movedinto engagement with this rim along all but a part of the bottom sidewhere the gasket on the door is omitted. As shown in FIG. 2, the gasket20 extends around the bottom corners from the sides and then terminatesunder the mufi le panel 18. Thus where the gasket is omitted an airinlet slot is provided adjacent the bottom edge of the door when closedto permit a limited quantity of air to be admitted into the oven whenthe door 12 is closed. The admission of this air is desirable bothduring normal cooking operations and during heat cleaning operations inthe oven.

The inner panel 16 (FIGS. 2 and 3) has an overall generally rectangularshape and is provided with a central, generally rectangular cutout areadefined by the inner peripheral flanged edge 24. A raised inner borderon the inside face of the inner panel encompasses the cutout area andprovides a shoulder 26 against which the inner border of the gasket 20seats when the gasket is assembled to the door. This shoulder 26 extendswithout interruption along the three sides of the cutout area of theinner panel. Along the hinged edge of the door the shoulders jutinwardly toward the cutout area to provide a pair of recesses 28 intowhich the ends of the gasket and framing wire is secured. These recessesare completely hidden by the mufile panel when it is applied.

The muflle panel 18 is a generally rectangular sheet which is drawn orotherwise formed in the shape of a shallow flat-bottomed pan withperipheral flanges 30 which overlap the shoulders 26 of the inner panelwith a limited width space between the flange 30 and shoulder 26 toaccommodate the beaded or enlarged inner border 32 of the gasket 20.

The gasket 20 is an open-ended, woven glass or asbestos fiber sleevewhich is generally circular in its unstressed form but, as supported andheld in the construction according to the invention, takes a flattenedform. The currently preferred glass fiber material is able to withstandhigh temperatures without deterioration, but, as noted, tends to abradeeasily as a result of the natural character of the glass fibers whichmake up the material. The sleeve is long enough to extend from onerecess 28 adjacent one corner of the muflle panel (FIG. 2), around threeconsecutive sides, and then terminate at the other recess (not shown inFIG. 2).

To hold the shape of the gasket, a wire frame 34 shaped as in FIG. 4 isused. The loops 36 at each end are accommodated in the recesses 28 ofthe inner panel and a sheet metal screw 38 (FIG. is turned through thegasket end and loop 36 into the inner panel to hold the Wire frame andgasket in place before assembling the muflle panel 18. A washer 40 isalso preferably used with the sheet metal screw to distribute theloading on the gasket fabric.

The wire frame 34 is sized so that with the gasket pushed down into aflattened condition, the wire extends around the inner margin of thegasket and forms the enlarged, head 32 which seats in the limited widthspace between the shoulders 26 of the inner panel and the peripheralflange 30 of the muffle panel.

The gasket is retained in its flattened cross-sectional shape by themufile panel peripheral flange 30. It is preferred that the size of thegap between the flange edge and the opposing face of the inner panel beequal to, or slightly greater than, a double thickness of the gasketmaterial. To hold the muffle panel relative to the inner panel with thisgap size, a bracket 42 (FIGS. 2 and 6) is provided between each cornerof the muflle panel and the inner panel. As shown in FIG. 6, thebrackets 42 are of a generally saddle-shape with wings which are securedby welding or otherwise bonding them to the hidden face of the mufllepanel 18. The bight portion of the bracket is secured to the inner panel16 by a screw fastener 44. In this way the panels are held together withthe proper spacing provided for the gap in which the gasket lies.

The gap is of course less than the diameter of the bead 32 formed alongthe inner border of the gasket by the wire frame 34 with the gasketmaterial encompassing the frame. Accordingly, the bead prevents thegaskets from being pulled out from underneath the muflie, and therelationship between the flange and the facing portions of the innerpanel hold the gasket in its properly flattened shape without damage tothe gasket material. It will also be appreciated that heat conductionfrom the muflle panel to the inner panel is limited, as a practicalmatter, to the paths provided by the brackets.

By way of summary then, a door construction according to the inventionis such that the characteristics of the woven fiber gasketing materialmay be taken advantage of, but with the construction being such that thedisadvantages of this type of material, with respect to problemsencountered in typical mounting arrangements, are substantiallyminimized.

I claim as my invention:

1. In an oven door construction:

an inner panel including shoulder means raised from the exposed face ofsaid panel and generally encompassing a central area ofsaid inner panel;

a muflle panel overlying said central area and having peripheral flangemeans directed toward said inner panel, said flange means lapping saidshoulder means slightly outwardly therefrom to define a limited widthspace therebetween, said flange means further defining a gap with theportion of the opposing face of said inner panel immediately outwardlyfrom said limited width space, said gap having a transverse dimensionsubstantially less than the transverse dimension of said limited widthspace;

a flexible tubular gasket having a length suflicient to follow the majorportion of the central area perimeter with the inner margin of thegasket disposed in said limited width space, and the remainder of saidgasket extending outwardly through said gap and being exposed beyond theperimeter of said muflle panel;

a wire frame extending longitudinally in said gasket inner margin toform an enlarged bead portion confined in and substantially occupyingsaid limited width space.

2. A door construction according to claim 1 wherein:

said shoulder means includes interrupted portions located to registerwith the ends of said wire frame to provide spaces for fastening theends of said wire frame to said inner panel in a hidden position beneathsaid muflle panel.

3. A door construction according to claim 1 wherein:

said gasket is of woven glass fiber material.

4. A door construction according to claim 3 including:

means for securing said muffle in spaced relation from said inner panelwith said gap defined between the edge of said muflle panel peripheralflange and the opposing face of said inner panel, said gap being lessthan the diameter of said gasket head, but at least as great as thedouble thickness dimension of said gasket material so that head isretained and the exposed portion of said gasket material is held ingenerally flattened condition but is not subjected to abrasive clampingby said muflle panel flange.

References Cited UNITED STATES PATENTS 3,099,259 7/1963 Newell 126-1902,219,962 10/1940 Reynolds et al 49479 2,665,458 1/1954 Wilcox 49-4793,127,890 4/1964 Mills 126-200 KENNETH W. SPRAGUE, Primary Examiner.

